Answer
27 degrees
Work Step by Step
We first find the maximum allowable velocity:
$6 = \frac{mv^2}{r} + mg$
$6 = \frac{(.5)v^2}{.45} + (.5)(9.81)$
$v=.9927 \ m/s$
Thus, we find the height that it can go:
$mgh = \frac{1}{2}mv^2 \\ h=\frac{v^2}{2g}=\frac{.9927^2}{2\times9.81}=.05$
Thus, we use trigonometry to find:
$cos\theta = \frac{.4}{.45} \\ \theta = 27.26^{\circ}$
